HDU 5384 字典树、AC自动机

题目：http://acm.hdu.edu.cn/showproblem.php?pid=5384

用字典树、AC自动机两种做法都可以做

#include<stdio.h>
#include<string.h>
#include<string>
#include<iostream>
using namespace std;
struct node{
    int cnt;
    node *next[26];
    node(){
        cnt = 0;
        for(int i = 0;i<26;i++)
            next[i] = NULL;
    }
}*a;
void insert(char *str){
    node *head = a;
    int len = strlen(str);
    for(int i = 0;i<len;i++){
        int temp = str[i]-'a';
        if(head->next[temp] == NULL)
            head->next[temp] = new node;
        head = head->next[temp];
    }
    head->cnt++;
}
int find(string t){
    node *head = a;
    int ans = 0;
    for(int i = 0;i<t.size();i++){
        if(head->next[t[i]-'a']){
            if(head->next[t[i]-'a']->cnt){
                ans++;
                
            }
        }else
            break;
        head = head->next[t[i]-'a'];
    }
    head->cnt--;
    return ans;
}
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        a = new node;
        int n;
        scanf("%d",&n);
        char s[55];
        for(int i = 0;i<n;i++){
            scanf(" %s",s);
            insert(s);
        }
        string des;
        cin >> des;
        int ans = 0;
        for(int i = 0;i<des.size();i++){
            ans += find(des.substr(i));
        }
        printf("%d
",ans);
    }
    return 0;
}

#include<stdio.h>
#include<string.h>
#include<string>
#include<iostream>
using namespace std;
struct node{
    int cnt;
    node *next[26];
    node(){
        cnt = 0;
        for(int i = 0;i<26;i++)
            next[i] = NULL;
    }
}*a;
void insert(char *str){
    node *head = a;
    int len = strlen(str);
    for(int i = 0;i<len;i++){
        int temp = str[i]-'a';
        if(head->next[temp] == NULL)
            head->next[temp] = new node;
        head = head->next[temp];
    }
    head->cnt++;
}
int find(string t){
    node *head = a;
    int ans = 0;
    for(int i = 0;i<t.size();i++){
        if(head->next[t[i]-'a']){
            if(head->next[t[i]-'a']->cnt){
                ans++;
                
            }
        }else
            break;
        head = head->next[t[i]-'a'];
    }
    head->cnt--;
    return ans;
}
int main(){
    int t;
    scanf("%d",&t);
    while(t--){
        a = new node;
        int n;
        scanf("%d",&n);
        char s[55];
        for(int i = 0;i<n;i++){
            scanf(" %s",s);
            insert(s);
        }
        string des;
        cin >> des;
        int ans = 0;
        for(int i = 0;i<des.size();i++){
            ans += find(des.substr(i));
        }
        printf("%d
",ans);
    }
    return 0;
}